Integrated lead suspension and method of construction

ABSTRACT

An integrated lead suspension includes a solder ball that is placed between a lead wiring pad provided on a flexure of the suspension, and a bonding pad provided on a slider of a head gimbal section. The lead wiring pad and bonding pad are soldered by melting the solder ball. As a result, there is provided a recessed section into which a solder ball is placed by way of surface raised sections, using gravitational force, in the vicinity of the center line of the surface of the lead wiring pad. In this way the position of the solder ball is not displaced from the center line when a bonding pad and lead wiring pad are connected by means of a solder ball.

BACKGROUND OF THE INVENTION

[0001] 1. Technical Field

[0002] The present invention relates to an integrated lead suspensionthat supports a magnetic head gimbal section of a hard disk drive, andmore particularly to an integrated lead suspension that can improveproblems that arise when a lead wiring pad provided on a flexure sectionof the suspension and a bonding pad provided on a slider of a headgimbal section of the suspension are joined.

[0003] 2. Description of the Related Art

[0004] As hard disk drives have become smaller in recent years, thedesign and construction of the various parts of the suspension thatmoves the magnetic head have become more difficult, and, in particular,the task of connecting leads to the slider that holds the magnetic headhas become extremely difficult. Moreover, the weight, wiring positions,and so forth, of the leads themselves have come to affect head control,and consequently integrated lead suspensions have come to be known inwhich variations due to wiring are suppressed by bonding a wiringsection, or forming a wiring pattern, on the suspension.

[0005] With an integrated lead suspension, it is necessary to jointogether a lead wiring pad provided on the flexure section on thesuspension side and a bonding pad provided on the slider, but the twoconnecting surfaces have a positional relationship such that theextended planes of the two pads are orthogonal (when the two planes areviewed from the side, a virtual right angle is formed at the point ofintersection), and therefore the technology for connecting normalopposing planes cannot handle this case, and various new technologiesare used.

[0006] For example, one known method for joining a lead wiring pad andbonding pad that have an orthogonal positional relationship is applebonding, using a gold (Au) ball. With apple bonding, a gold ball ispushed into the virtual right angle formed by the above-described twopads, and connection is made by means of ultrasonic welding. An exampleof another method is a method using a solder ball for which applicationhas been made by the present applicants in Japanese Patent ApplicationNo. 2000-189148 or Japanese Patent Application No. 2001-039888.

[0007] With a method using a solder ball, the integrated lead suspensionis supported so that the virtual right angle formed by theabove-described two pads faces upward vertically, and a solder ball isplaced between the two pads. Following this, the solder is melted byirradiating the solder ball with a laser beam, connecting the two pads.

[0008]FIG. 15 is a drawing showing the case where the lead wiring padand bonding pad are joined using a solder ball in a conventionalintegrated lead suspension. A suspension flexure 5 has a 2-layerconstruction comprising a polyimide layer 17, which is insulatingpolymeric material, and a stainless steel foil layer 18. A lead 10,which is a conductive layer, is further formed on the polyimide layer17, and at the end of the lead 10 is formed a lead wiring pad 12 that iswider than the lead 10 so as to be of sufficient area for solderconnection.

[0009] The shape of the polyimide layer 17 and stainless steel foillayer 18 can be processed by performing etching, for example, aftercoating the necessary parts with a resist. Also, when the polyimidelayer 17 is a photosensitive polyimide layer, the shape can be processedby performing exposure and development after coating the necessary partsof the polyimide layer 17 with a resist or the like.

[0010] An aperture section 11 is formed in the tip section of the leadwiring pad 12 on the flexure 5 in order to prevent such problems asoverflow of adhesive adhering to the lead wiring pad 12 when the slideris bonded to the suspension, or the polymeric polyimide layer 17 beingaltered by heat emission due to laser beam radiation. Therefore, the tipsection of the lead wiring pad 12 comprises in-air wiring that projectsinto the aperture section 11.

[0011] A slider 6 that incorporates a magnetic head for a hard disk isattached to the flexure 5, and a bonding pad 15 of the slider 6 isplaced in a position orthogonal to the lead wiring pad 12 as describedabove. Thus, the virtual orthogonal axes at which the plane extendedfrom the plane of the bonding pad 15 intersects the plane extended fromthe plane of the lead wiring pad 12 form an angle of 90 degrees (a rightangle).

[0012] When the bonding pad 15 and lead wiring pad 12 are connected witha solder ball, the suspension (flexure 5) is fixed in the direction inwhich the virtual right angle formed by the bonding pad 15 and leadwiring pad 12 opens upward in a vertical direction. Normally, theflexure 5 is fixed so that the lead wiring pad 12 on the flexure 5 andthe bonding pad 15 on the slider 6 both form an angle 45 degrees abovethe horizontal while both maintaining a state in which the positionalrelationship of the two is orthogonal. Then a solder ball 400 is droppedfrom a solder ball transfer apparatus (not shown) between the two fixedpads. The two pads are then connected by melting the solder ball 400 byheating it by means of a laser beam radiation apparatus or the like (notshown).

[0013] With a conventional integrated lead suspension, the bonding pad15 and lead wiring pad 12 are connected by means of a solder ball inthis way. Integral-type wiring suspensions are classified into the threetypes below according to differences in their construction methods. Inthe construction of all three types, connection is performed asdescribed above when the bonding pad 15 and lead wiring pad 12 areconnected by means of a solder ball.

[0014] (a) An additive type in which copper foil wiring and pads areadditively formed on insulating material of the suspension

[0015] (b) A subtractive type in which wiring and pads are formed bybeing etched from copper foil formed as a sheet on insulating materialof the suspension

[0016] (c) An FPC type in which a flexible substrate (FPC) on whichcopper foil wiring and pads are formed is bonded to the suspension

[0017] However, with a conventional integrated lead suspension, when thebonding pad 15 and lead wiring pad 12 are connected by means of a solderball there is problem in that, since the solder ball is almost sphericaland the surfaces of the bonding pad 15 and lead wiring pad 12 are almostflat, the solder ball rolls in the virtual right-angle axis direction(direction A or direction B in FIG. 15) at which the extended planes ofthe two pads are orthogonal, and the position of the solder ball isdisplaced from the center line CL of each pad shown in FIG. 15. Thisproblem arises in a similar way with all the above-described types.

[0018] Also, with the additive type, in particular, die wear occurswhereby areas near the edge take on an inclined beveled shape as shownin 12 a through 12 c in FIG. 15, as a result of which the area of theflat section 12 d diminishes, and moreover, the surface of remainingflat section 12 d is rough and has undulations. Consequently, theadditive type is more susceptible than the other types to the problem ofdisplacement of the position of the solder ball from the center line CL.

[0019] If the position of the solder ball is displaced from the centerline, when the two pads are connected by melting the solder ball withlaser beam radiation, there arises a solderless state in which there isno solder ball in the connecting region, or a solder connection defectbecause the solder ball, although in the connecting region, is displacedfrom the center line. Solder connection defects may include, in the casewhere solder does not connect both pads, partial soldering in which onlyparts of the two pads are imperfectly soldered, or a bridge connectionthat connects adjacent pads of the same kind.

[0020] The present invention has been devised in order to solve suchconventional problems as described above, and has as its object theprovision of an integrated lead suspension whereby, when a bonding padand lead wiring pad are connected by means of a solder ball, theposition of the solder ball is not displaced from the center line.

SUMMARY OF THE INVENTION

[0021] In order to achieve the above-described object, an integratedlead suspension of the present invention comprises a lead wiring padprovided on the flexure section of the suspension, a bonding padprovided on the slider of the head gimbal section of the suspension, anda solder ball that is placed between the lead wiring pad and the bondingpad, so that the lead wiring pad and bonding pad are soldered by meltingthe solder ball; and a recessed section is provided into which thesolder ball is dropped from the surface of the lead wiring pad, usingthe force of gravity, in the vicinity of the center line of the surfaceof the lead wiring pad.

[0022] The recessed section of an integrated lead suspension of thepresent invention may be configured so that a difference in level, acurved surface, or an inclined surface is formed between the part intowhich the solder ball is dropped and the portions on both sides thereof.

[0023] The recessed section of an integrated lead suspension of thepresent invention may be configured so that the distances from thecenter line of the part into which the solder ball is dropped to theportions on both sides thereof are equal.

[0024] The recessed section of an integrated lead suspension of thepresent invention may have the part into which the solder ball isdropped that has a groove shape parallel to the center line or a notchedsection.

[0025] The recessed section of an integrated lead suspension of thepresent invention may have the part into which the solder ball isdropped that has a U-shape with the opening side facing downward and theportions on both sides thereof parallel to the center line, or a V-shapewith the opening side facing downward and the portions on both sidesthereof extending from the apex positioned on the center line toward theopening side.

[0026] A construction method of an integrated lead suspension of thepresent invention comprises providing a lead wiring pad on a flexuresection of the suspension, providing a bonding pad on a slider of a headgimbal section of the suspension, and placing a solder ball between thelead wiring pad and the bonding pad, so that the solder ball is meltedto solder the lead wiring pad and bonding pad together, and when a leadwiring pad is formed using etching technology, a recessed section issimultaneously formed into which a solder ball is dropped from thesurface of the lead wiring pad, using the force of gravity, in thevicinity of the center line of the surface of that lead wiring pad.

[0027] A construction method of an integrated lead suspension of thepresent invention may comprise providing a lead wiring pad a flexuresection of the suspension, providing a bonding pad on a slider of a headgimbal section of the suspension, and placing a solder ball between thelead wiring pad and the bonding pad, so that the solder ball is meltedto solder the lead wiring pad and bonding pad together wherein theconstruction method may comprise the steps of: first forming a leadwiring pad having a flat surface, and thereafter providing a recessedsection into which a solder ball is dropped from the surface of the leadwiring pad, using the force of gravity, in the vicinity of the centerline of the surface of the lead wiring pad.

[0028] A construction method of an integrated lead suspension of thepresent invention may provide a recessed section using etchingtechnology, bending, or die press working.

[0029] When an integrated lead suspension of the present invention is ofadditive type, the construction method may comprise the steps of: firstforming a lead wiring pad having a flat surface using copper platingtechnology, and thereafter causing protrusion by plating additionalcopper on the portions on both sides thereof excluding the vicinity ofthe center line of the surface of the lead wiring pad and providing arelatively recessed section.

[0030] When an integrated lead suspension of the present invention is ofadditive type, the construction method may comprise the steps of: firstforming an underlying recessed section using etching technology on anunderlying layer of the lead wiring pad, and thereafter forming arecessed section by forming a lead wiring pad using copper platingtechnology on that underlying layer.

BRIEF DESCRIPTION OF THE DRAWINGS

[0031]FIG. 1 is an oblique drawing showing the overall configuration ofan integrated lead suspension according to Embodiment 1 of the presentinvention;

[0032]FIG. 2 is an expanded partial drawing of the tip section on whicha slider is located in the integrated lead suspension shown in FIG. 1;

[0033]FIG. 3 is a cross-sectional drawing showing a solder ball joiningapparatus that connects two pads by irradiating a solder ball placedbetween the two pads with a laser beam;

[0034]FIG. 4 is a cross-sectional drawing showing an enlarged view ofthe state where a solder ball is positioned at the tip section of anintegrated lead suspension supported by the work jig shown in FIG. 3;

[0035]FIG. 5 is a cross-sectional drawing showing an enlarged view ofthe state where the solder ball shown in FIG. 4 has melted and joined abonding pad and a lead wiring pad;

[0036]FIG. 6 is an oblique drawing showing an enlarged view of the mainparts in an integrated lead suspension according to Embodiment 1 of thepresent invention;

[0037]FIG. 7 is an oblique drawing showing an enlarged view of the mainparts in an integrated lead suspension according to Embodiment 2 of thepresent invention;

[0038]FIG. 8 is an oblique drawing showing an enlarged view of the mainparts in an integrated lead suspension according to Embodiment 3 of thepresent invention;

[0039]FIG. 9 is an oblique drawing showing an enlarged view of the mainparts in an integrated lead suspension according to Embodiment 4 of thepresent invention;

[0040]FIG. 10 is an oblique drawing showing an enlarged view of the mainparts in an integrated lead suspension according to Embodiment 5 of thepresent invention;

[0041]FIG. 11 is an oblique drawing showing an enlarged view of the mainparts in an integrated lead suspension according to Embodiment 6 of thepresent invention;

[0042]FIG. 12(A) is a drawing showing pads of the same kind asconventional lead wiring pads during the process of manufacture, andFIG. 12(B) is an oblique drawing showing an enlarged view of the mainparts in an integrated lead suspension according to Embodiment 7;

[0043]FIG. 13(A) is a drawing showing pad base sections formed byetching, etc., on a polyimide layer, which is insulating polymericmaterial, during the process of manufacture, and FIG. 13(B) is anoblique drawing showing an enlarged view of the main parts in anintegrated lead suspension according to Embodiment 8;

[0044]FIG. 14(A) is a drawing showing pad base sections formed byetching, etc., on a polyimide layer, which is insulating polymericmaterial, during the process of manufacture, and FIG. 14(B) is anoblique drawing showing an enlarged view of the main parts in anintegrated lead suspension according to Embodiment 9; and

[0045]FIG. 15 is a drawing showing the case where a lead wiring pad andbonding pad are joined using a solder ball in a conventional integratedlead suspension.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

[0046] The present invention will now be described in detail based onthe embodiments shown in the attached drawings.

[0047]FIG. 1 is an oblique drawing showing the overall configuration ofan integrated lead suspension according to Embodiment 1 of the presentinvention, and FIG. 2 is an expanded partial drawing of the tip sectionon which a slider is located in the integrated lead suspension shown inFIG. 1.

[0048] An integrated lead suspension 1 mainly comprises a base plate 2,load beam 4, suspension plate 3, and flexure 5. An aperture section 2 aformed in the base plate 2 is supported by suspension support means of ahard disk drive (not shown), and the integrated lead suspension 1rotates in the directions of arrows R, centered on the aperture section2 a.

[0049] The suspension plate 3 is bonded to the base plate 2, and theload beam 4 is fixed to the suspension plate 3. The suspension plate 3is flexibly supported by the base plate 2, and the desired suspensioncharacteristics are obtained by means of the formed aperture section.The load beam 4 is extended in a direction radiating from the axis ofrotation about which the integrated lead suspension 1 rotates, and a tab7 is formed on its tip section.

[0050] The flexure 5 is a lead support mechanism that extends in a crankshape from the tip section of the integrated lead suspension 1 to amulti-connector section 9, and is laser-welded to the load beam 4 atthree places and is also fixed to the base plate 2. On the upper surfaceof this flexure 5 (the surface uppermost in FIG. 1), four leads 8 arearranged via an insulating sheet so as not to be in mutual contact. Theprincipal parts of these leads are protected by a protective sheet.

[0051] The vicinity of the tip section of the flexure 5 is fixed to theload beam 4, but the leads forward of that fixed part are free of theload beam 4, and here an arch-shaped aperture section is formed. Theslider 6 is bonded to a flexure tang 14 that is formed projecting towardthe center of the arch-shaped aperture section from a platform 13 of themost forward part of the flexure 5.

[0052] As regards this flexure tang 14, a position at the center of theslider 6 is supported by a pivot (not shown) projecting from the loadbeam 4. By this means, the slider 6 can maintain predetermined amountsof inclination (called pitch, roll, and yaw) in all directions withrespect to the load beam 4.

[0053] The four leads 8 shown in FIG. 1 are divided into pairs of leads10 from where they emerge from the protective sheet toward the mostforward part as shown in FIG. 2, and arrive at the platform 13 afterbending through almost a right angle, floating free, at the side of theaperture section 11. On the platform 13, the leads 10 bend again throughalmost a right angle toward four bonding pads 15 formed on the mostforward side 6 a of the slider 6.

[0054] At the end of each bent lead 10 is formed a lead wiring pad 20that is to be connected to a bonding pad 15 formed on the most forwardside 6 a of the slider 6. An aperture section 11 is formed between theplatform 13 and flexure tang 14, which is the solder connection area forthe bonding pads 15 and lead wiring pads 20.

[0055] Next, the method of connecting a bonding pad 15 and lead wiringpad 20 using a solder ball will be described. In summary, the integratedlead suspension 1 is first supported so that the right angle formed atthe intersection of the surface (connecting surface) of a bonding pad 15and the surface (connecting surface) of a lead wiring pad 20 facesupward in a vertical direction, and then a solder ball is placed betweenthe two pads, after which the two pads are connected by irradiating thesolder ball with a laser beam.

[0056] First, the method will be described below whereby the integratedlead suspension 1 is supported so that the right-angle section formed bythe surface of a bonding pad 15 and the surface of a lead wiring pad 20faces upward in a vertical direction.

[0057]FIG. 3 is a cross-sectional drawing showing a solder ball joiningapparatus that connects the two pads by irradiating a solder ball placedbetween the two pads with a laser beam. This is a main configurationdrawing showing an approaching optical (laser) apparatus 200 that is toirradiate the solder ball 400 with a laser beam 201, a work jig 301 thatsupports the integrated lead suspension 1, and a mounting stand 300 thatsupports this work jig 301.

[0058] The mounting stand 300 has a mounting surface 300 a at a45-degree incline to the horizontal plane H, and the work jig 301 isplaced on this mounting surface 300 a so that it is also at a 45-degreeincline to the horizontal plane H. The slider 6 is placed on the workjig 301, and the integrated lead suspension 1 is mounted with the slider6 toward its upper surface.

[0059] At this time, in the integrated lead suspension 1 supported bythe work jig 301, the joining surfaces of the bonding pads at its tipsection and the joining surfaces of the opposing lead wiring pads are atpractically 45 degrees to the horizontal plane. In this way, the virtualright-angle section formed by the surface of a bonding pad 15 and thesurface of a lead wiring pad 20 is supported so as to open toward theupper part of the vertical direction V on the work jig 301.

[0060] Next, a solder ball 400 is placed between the two pads, and thenthe solder ball 400 is irradiated with a laser beam 201. As the methodof placing the solder ball 400 between the two pads and performing laserbeam 201 radiation is disclosed in detail by the present applicants inJapanese Patent Application No. 2000-189148 and Japanese PatentApplication No. 2001-039888, and the method of placing the solder ball400, the configuration of the optical apparatus 200, and so forth, arenot directly relevant to the present application, only a briefdescription thereof will be given here.

[0061] The optical apparatus 200 is a fiber laser termination modulethat uses an optical fiber in a resonator, has a series of opticallenses arranged in an internal optical path, and forms an aerial laserbeam path space. The optical lenses converge scattered light output fromthe optical fiber, and output this as a laser beam 201 from the forwardsection of the optical apparatus 200.

[0062]FIG. 4 is a cross-sectional drawing showing an enlarged view ofthe state where a solder ball is positioned at the tip section of theintegrated lead suspension 1 supported by the work jig 301 shown in FIG.3. A bonding pad 15 and lead wiring pad 20 are positioned so as to eachbe raised 45 degrees above the horizontal plane, the plane extended fromthe surface of the bonding pad 15 and the plane extended from thesurface of the lead wiring pad 20 are orthogonal, and a virtual rightangle is formed between the two pads. The virtual right angle openstoward the top of the vertical direction V, and is set to an anglesuitable for catching a solder ball 400 supplied from above.

[0063] When a solder ball 400 transported by means of suction pad isplaced, and comes to rest, so as to touch the joining surfaces of thebonding pad 15 and lead wiring pad 20, the optical apparatus 200 ismoved to the radiation position by means of moving means (not shown),and the solder ball 400 is irradiated with a laser beam 201 converged toa predetermined spot diameter.

[0064] In the period from placement of this solder ball 400 until it isirradiated with the laser beam 201, a predetermined quantity of nitrogengas N₂ constituting an inert atmosphere is injected from a nitrogen gasentry pipe of the mounting stand 300 in order to suppress solderoxidation. By this means, the bonding pad 15, lead wiring pad 20, andsolder ball 400 are placed in an inert atmosphere. When nitrogen gas isinjected, the injection location and flow rate are considered to preventa change in the position of the stationary solder ball due to the gaspressure during injection, but even so, the solder ball may move due tothe injection of nitrogen gas if the surface condition of the pads ispoor, for example.

[0065] While this inert atmosphere is maintained, the optical apparatus200 emits a laser beam 201 and melts the solder ball 400 by heating it,so connecting the bonding pad 15 and lead wiring pad 20. If the externaldiameter of the solder ball is around 120 mm, for example, the spotdiameter of the laser beam at this time is set to around 150 to 200 mm.

[0066] As a result of melting the solder in an inert atmosphere producedby nitrogen gas N₂ in this way, inert nitrogen gas N₂ coats the soldersurface when the solder cools and forms a joint after melting, thusenabling oxidation of the solder to be prevented.

[0067]FIG. 5 is a cross-sectional drawing showing an enlarged view ofthe state where the solder ball shown in FIG. 4 has melted and joinedthe bonding pad 15 and lead wiring pad 20. The melted solder 401 spreadsupward on both the bonding pad 15 connecting surface and the lead wiringpad 20 connecting surface due to the wettability of the solder, andforms a shape that connects the two pads. The melted solder spreads tothe front surface at the top of both the bonding pad 15 connectingsurface and the lead wiring pad 20 connecting surface, and if the twoare connected in an inverted arch shape as shown in FIG. 5, a fillet 401showing a good connection state is formed. In order for a goodconnection state such as that shown in FIG. 5 to be achieved, the solderball 400 must be placed in the vicinity of the center line of the sidedirection (virtual right angle axis direction) on each pad.

[0068]FIG. 6 is an oblique drawing showing an enlarged view of the mainparts in an integrated lead suspension of this embodiment, and shows thearea where a lead wiring pad and bonding pad are joined using a solderball. The difference between the integrated lead suspension of thisembodiment shown in FIG. 6 and the conventional integrated leadsuspension shown in FIG. 15 lies only in the structure of the leadwiring pads 20. Otherwise the configuration is the same as that of theconventional integrated lead suspension shown in FIG. 15.

[0069] With a lead wiring pad 20 of this embodiment, the same kind ofpad as a conventional lead wiring pad shown in FIG. 15 is first formed,and then etching is further performed on its surface. A pad of the samekind as a conventional lead wiring pad is formed, in the case of asubtractive type or FPC type integrated lead suspension, by coatingareas requiring a Cu (copper) foil layer with a resist, etching otherparts, and then removing the resist; and in the case of an additive typeintegrated lead suspension, by setting a seed layer on a polyimide layer17 by means of sputtering, performing Cu (copper) plating after coatingunnecessary areas thereupon with a resist, and then removing the resist.In this embodiment, following this, half-etching is performed aftercoating raised section 22 and raised section 23 with another resist, andthe recessed groove section (recessed section) 21 shown in FIG. 6 isprovided on the lead wiring pads 20.

[0070] As a result, a recessed groove section 21 is formed byhalf-etching along the center line CL in a lead wiring pad 20 of thisembodiment, and unetched raised section 22 and raised section 23 remainon either side of the recessed groove section 21, so that a differencein level is provided between the recessed groove section 21 and raisedsection 22 and between the recessed groove section 21 and raised section23.

[0071] This difference in level need not be a sharply-defined differencein level as shown in FIG. 6, but, for example, may be configured so thatthe recessed groove section 21 sinks gently below raised section 22 andraised section 23 on a curved surface, or may be configured so that therecessed groove section 21 sinks gently below raised section 22 andraised section 23 on an inclined surface.

[0072] Due to the formation of this difference in level, a solder ball400 is dropped into the recessed groove section 21—that is, betweenraised section 22 and raised section 23—under the force of gravity, andis temporarily fixed so that the center of the solder ball 400substantially coincides with the center line CL on the recessed groovesection 21 and does not move in the virtual right angle axis directionbetween the two pads. As a result, the solder ball 400 will no longermove even if subjected to some kind of stress in the virtual right angleaxis direction (direction A or direction B shown in FIG. 6) due to thesubsequent injection of nitrogen gas, etc., or vibration when theoptical apparatus 200 moves, for example.

[0073] As the dimensions of the recessed groove section 21, if, forexample, the width of a lead wiring pad 20 is 148 mm and the diameter ofthe solder ball is 120 mm, a width (74 mm) of half the width of a leadwiring pad 20 and a thickness of half the thickness of a lead wiring pad20 are appropriate.

[0074] In this embodiment, a difference in level is provided between arecessed groove section 21 in the vicinity of the center line CL and theperipheral areas by etching on a lead wiring pad 20, but the recessedgroove section 21 may also be formed not by providing a difference inlevel with respect to peripheral areas by etching, but, for example, bysinking the vicinity of the center line CL gently on a curved surfacethat continues from the peripheral areas, or by sinking the vicinity ofthe center line CL on an incline from the peripheral areas toward thevicinity of the center line CL.

[0075] In this embodiment, a recessed groove section 21 is formed usinghalf-etching around the center line CL of a lead wiring pad 20, butanother shape may also be formed by etching, as long as it is a shapethat allows a solder ball 400 to be dropped into it by force of gravity.For example, an oval or circular recessed section, or a rhomboidal orrectangular recessed section, may be provided in the vicinity of thecenter of a lead wiring pad 20 by etching.

[0076] Thus, with an integrated lead suspension of this embodiment,through the provision of a recessed groove section 21 in a lead wiringpad 20 by means of half-etching, the center of a solder ball 400substantially coincides with the center line CL of the lead wiring pad20, and is temporarily fixed so that it does not move in the virtualright angle axis direction between the two pads, as a result of whichthe solder ball 400 will no longer move in the right angle axisdirection even if subjected to some kind of stress in the virtual rightangle axis direction due to subsequent injection of an inert gas ormovement of the optical apparatus 200, for example, thereby enabling thegood solder connection state shown in FIG. 5 to be achieved.

[0077]FIG. 7 is an oblique drawing showing an enlarged view of the mainparts in an integrated lead suspension according to Embodiment 2 of thepresent invention. The only difference between this embodiment andEmbodiment 1 is that the shape of the lead wiring pads 30 is different.Otherwise the configuration is the same as that of the integrated leadsuspension according to Embodiment 1 shown in FIGS. 1-6.

[0078] A lead wiring pad 30 of this embodiment is formed, in the case ofa subtractive type or FPC type integrated lead suspension, by coatingareas requiring a Cu (copper) foil layer with a resist, etching otherparts, and then removing the resist; and in the case of an additive typeintegrated lead suspension, by setting a seed layer on a polyimide layerby means of sputtering, performing Cu (copper) plating after coatingunnecessary areas thereupon with a resist, and then removing the resist.At this time, the U-shaped notched section (recessed section) 31 shownin FIG. 7 is formed in each lead wiring pad 30 by changing the resist.

[0079] The U-shaped notched section 31 is formed so that thestraight-line parts of a U with the aperture facing downward areparallel to the center line CL. On either side of the U-shaped notchedsection 31 a fork section (raised section) 32 and fork section (raisedsection) 33 are formed, and a space parallel to the center line CL isformed by the U-shaped notched section 31 between fork section 32 andfork section 33.

[0080] Due to the formation of this space by the U-shaped notchedsection 31, a solder ball 400 is dropped into the U-shaped notchedsection 31—that is, between fork section 32 and fork section 33—underthe force of gravity, and is temporarily fixed so that the center of thesolder ball 400 substantially coincides with the center line CL on theU-shaped notched section 31 and does not move in the virtual right angleaxis direction between the two pads. As a result, the solder ball 400will no longer move even if subjected to some kind of stress in thevirtual right angle axis direction (direction A or direction B shown inFIG. 7) due to the subsequent injection of nitrogen gas, etc., orvibration when the optical apparatus 200 moves, for example.

[0081] As the width of the section parallel to the center line CL in theU-shaped notched section 31, if, for example, the width of a lead wiringpad 30 is 148 mm and the diameter of the solder ball is 120 mm, a widthof half (74 mm) or ⅓ (approx. 49 mm) the width of a lead wiring pad 30is appropriate. As for the curved section of the U-shaped notchedsection 31, any arc-shaped curve can be used that enables the parallelsections on either side to be connected.

[0082] In this embodiment, a U-shaped notched section 31 is formedperipheral to the center line CL of a lead wiring pad 30, but adifferent shape may also be formed as long as it is a shape that enablesa solder ball 400 to be dropped into it under the force of gravity. Forexample, an oval or circular notched section may be provided in thevicinity of the center of a lead wiring pad 30.

[0083] Thus, with an integrated lead suspension of this embodiment,through the provision of a U-shaped notched section 31 in a lead wiringpad 30, in the same way as in above-described Embodiment 1, the centerof a solder ball 400 substantially coincides with the center line CL ofthe lead wiring pad 30, and is temporarily fixed so that it does notmove in the virtual right angle axis direction between the two pads, asa result of which the solder ball 400 will no longer move in the rightangle axis direction even if subjected to some kind of stress in thevirtual right angle axis direction due to subsequent injection of aninert gas or movement of the optical apparatus 200, for example, therebyenabling the good solder connection state shown in FIG. 5 to beachieved.

[0084]FIG. 8 is an oblique drawing showing an enlarged view of the mainparts in an integrated lead suspension according to Embodiment 3 of thepresent invention. The only difference between this embodiment andEmbodiment 2 is that the shape of the lead wiring pads 40 is different.Otherwise the configuration is the same as that of the integrated leadsuspension according to Embodiment 2 shown in FIG. 7.

[0085] As the method of forming a lead wiring pad 40 of this embodiment,in the same way as in the Embodiment 2, in the case of a subtractivetype or FPC type integrated lead suspension, the pad is formed byetching parts not coated with a resist, and in the case of an additivetype integrated lead suspension, by performing Cu (copper) plating ofparts not coated with a resist. At this time, the V-shaped notchedsection (recessed section) 41 shown in FIG. 8 is formed in each leadwiring pad 40 by changing the resist.

[0086] The V-shaped notched section 41 is formed so that the aperture ofa V with the opening side facing downward is at the tip of the leadwiring pad 40, and a straight line from the apex of the V through themidpoint of the two sides of the aperture of the V coincides with thecenter line CL. On either side extending from the apex of the V of theV-shaped notched section 41 toward the aperture of the V, a fork section(raised section) 42 and fork section (raised section) 43 are formed, anda space that gradually widens as it approaches the connecting area isformed by the V-shaped notched section 31 between fork section 42 andfork section 43.

[0087] Due to the formation of this space by the V-shaped notchedsection 41, a solder ball 400 is dropped into the V-shaped notchedsection 41—that is, between fork section 42 and fork section 43—underthe force of gravity, and is temporarily fixed so that the center of thesolder ball 400 substantially coincides with the center line CL on theV-shaped notched section 41 and does not move in the virtual right angleaxis direction between the two pads. As a result, the solder ball 400will no longer move even if subjected to some kind of stress in thevirtual right angle axis direction (direction A or direction B shown inFIG. 8) due to the subsequent injection of nitrogen gas, etc., orvibration when the optical apparatus 200 moves, for example.

[0088] As the width of the section parallel to the center line CL in theV-shaped notched section 41, if, for example, the width of a lead wiringpad 40 is 148 mm and the diameter of the solder ball is 120 mm, theangle of the V-shaped notched section 41 should be determined so as tocontact the lead wiring pad 40 at a point where the width is ⅓ (approx.49 mm) the width of a lead wiring pad 40.

[0089] In this embodiment, a V-shaped notched section 41 is formedperipheral to the center line CL of a lead wiring pad 40, but adifferent shape may also be formed as long as it is a shape that enablesa solder ball 400 to be dropped into it under the force of gravity. Forexample, a rectangular or rhomboidal notched section may be provided inthe vicinity of the center of a lead wiring pad 40.

[0090] Thus, with an integrated lead suspension of this embodiment,through the provision of a V-shaped notched section 41 in a lead wiringpad 40, in the same way as in the other embodiments described above, thecenter of a solder ball 400 substantially coincides with the center lineCL of the lead wiring pad 40, and is temporarily fixed so that it doesnot move in the virtual right angle axis direction between the two pads,as a result of which the solder ball 400 will no longer move in theright angle axis direction even if subjected to some kind of stress inthe virtual right angle axis direction due to subsequent injection of aninert gas or movement of the optical apparatus 200, for example, andmoreover, the fact that the shape of the V-shaped notched section 41 isa V also makes it difficult for the solder ball 400 to move toward theapex of the V, and so makes the solder ball 400 all the more stable,thereby enabling the good solder connection state shown in FIG. 5 to beachieved.

[0091]FIG. 9 is an oblique drawing showing an enlarged view of the mainparts in an integrated lead suspension according to Embodiment 4 of thepresent invention. The only difference between this embodiment andEmbodiment 1 is that the shape of the lead wiring pads 50 is different.Otherwise the configuration is the same as that of the integrated leadsuspension according to Embodiment 1 shown in FIGS. 1 through 6.

[0092] With a lead wiring pad 50 of this embodiment, the same kind ofpad as a conventional lead wiring pad shown in FIG. 15 is first formed,in the same way as in Embodiment 1, and then bending is furtherperformed on that pad. The method of forming a pad of the same kind as aconventional lead wiring pad is the same as in Embodiment 1. In thisembodiment, following this, the lead wiring pads 50 are further deformedusing a die or the like (not shown), and the bent section 51 shown inFIG. 9 is formed in each lead wiring pad 50.

[0093] As a result, a bent section (recessed section) 51 is formed alongthe center line CL in each lead wiring pad 50 of this embodiment, and oneither side of the bent section 51 are formed an inclined section(raised section) 52 and inclined section (raised section) 53 slopingtoward the bent section 51.

[0094] As the bent section 51 is linear in shape and is formed so as tocoincide with the center line CL, and inclined section 52 and inclinedsection 53 on either side of the bent section 51 slope toward the bentsection 51, a solder ball 400 is dropped into the bent section 51—thatis, between inclined section 52 and inclined section 53—under the forceof gravity, and is temporarily fixed so that the center of the solderball 400 substantially coincides with the center line CL on the bentsection 51 and does not move in the virtual right angle axis directionbetween the two pads. As a result, the solder ball 400 will no longermove even if subjected to some kind of stress in the virtual right angleaxis direction (direction A or direction B shown in FIG. 9) due to thesubsequent injection of nitrogen gas, etc., or vibration when theoptical apparatus 200 moves, for example.

[0095] In this embodiment, a single bent section 51 is formed coincidentwith the center line CL of a lead wiring pad 50, but a plurality of bentsections may also be formed centered on the center line CL, as long astheir shape enables a solder ball 400 to be dropped into them under theforce of gravity.

[0096] Also, the bent section 51 is not limited to the case where a bendis made in a straight line as shown in FIG. 9, and the bent section 51may also be configured, for example, so as to sink gently on a curvedsurface.

[0097] Thus, with an integrated lead suspension of this embodiment,through the provision of a bent section 51 in a lead wiring pad 50, inthe same way as in the other embodiments described above, the center ofa solder ball 400 substantially coincides with the center line CL of thelead wiring pad 50, and is temporarily fixed so that it does not move inthe virtual right angle axis direction between the two pads, as a resultof which the solder ball 400 will no longer move in the right angle axisdirection even if subjected to some kind of stress in the virtual rightangle axis direction due to subsequent injection of an inert gas ormovement of the optical apparatus 200, for example, thereby enabling thegood solder connection state shown in FIG. 5 to be achieved.

[0098]FIG. 10 is an oblique drawing showing an enlarged view of the mainparts in an integrated lead suspension according to Embodiment 5 of thepresent invention. The only difference between this embodiment andEmbodiment 4 is that the shape of the lead wiring pads 60 is different.Otherwise the configuration is the same as that of the integrated leadsuspension according to Embodiment 4 shown in FIG. 9.

[0099] With a lead wiring pad 60 of this embodiment, the same kind offlat pad as a conventional lead wiring pad shown in FIG. 15 is firstformed, in the same way as in Embodiment 4, and then bending isperformed on its surface, but in this embodiment both sides of the padhave a bent section. The method of forming a pad of the same kind as aconventional lead wiring pad is the same as in Embodiment 1 orEmbodiment 4. In this embodiment, following this, the lead wiring pads60 are further deformed using a die or the like (not shown), and a bentsection 62 and bent section 63 are bent upward from each lead wiring pad60 as shown in FIG. 10. As a result, a bent section (raised section) 62and bent section (raised section) 63, bent upward and parallel to thecenter line CL, are formed on either side of the flat section 61(recessed section) on each lead wiring pad 60 of this embodiment.

[0100] As bent section 62 and bent section 63 are rectangular and formedso that the long sides are parallel to the center line CL, and are bentupward, a solder ball 400 is dropped onto the flat section 61—that is,between bent section 62 and bent section 63—under the force of gravity,and is temporarily fixed so that the center of the solder ball 400substantially coincides with the center line CL on the flat section 61and does not move in the virtual right angle axis direction between thetwo pads. As a result, the solder ball 400 will no longer move even ifsubjected to some kind of stress in the virtual right angle axisdirection (direction A or direction B shown in FIG. 9) due to thesubsequent injection of nitrogen gas, etc., or vibration when theoptical apparatus 200 moves, for example.

[0101] In this embodiment, a bent section 62 and bent section 63 areformed parallel to the center line CL on a lead wiring pad 60, but abent section 62 and bent section 63 may also be formed at a slopingangle centered on the center line CL, as long as their shape enables asolder ball 400 to be dropped between them under the force of gravity.

[0102] Thus, with an integrated lead suspension of this embodiment,through the provision of a bent section 62 and bent section 63 on a leadwiring pad 60, in the same way as in the other embodiments describedabove, the center of a solder ball 400 substantially coincides with thecenter line CL of the lead wiring pad 60, and is temporarily fixed sothat it does not move in the virtual right angle axis direction betweenthe two pads, as a result of which the solder ball 400 will no longermove in the right angle axis direction even if subjected to some kind ofstress in the virtual right angle axis direction due to subsequentinjection of an inert gas or movement of the optical apparatus 200, forexample, thereby enabling the good solder connection state shown in FIG.5 to be achieved.

[0103]FIG. 11 is an oblique drawing showing an enlarged view of the mainparts in an integrated lead suspension according to Embodiment 6 of thepresent invention. The only difference between this embodiment andEmbodiment 1 is that the shape of the lead wiring pads 70 is different.Otherwise the configuration is the same as that of the integrated leadsuspension according to Embodiment 1 shown in FIGS. 1-6.

[0104] With a lead wiring pad 70 of this embodiment, the same kind ofpad as a conventional lead wiring pad shown in FIG. 15 is first formed,in the same way as in Embodiment 1, and then press working is furtherperformed on that pad. The method of forming a pad of the same kind as aconventional lead wiring pad is the same as in Embodiment 1. In thisembodiment, following this, the lead wiring pads 70 are furtherpress-deformed using a die or the like (not shown), and the sunkensection (recessed section 71 shown in FIG. 11 is formed in each leadwiring pad 70. As a result, a sunken section 71 is formed along thecenter line CL in each lead wiring pad 70 of this embodiment, and oneither side of the sunken section 71 are formed a raised section 72 anda raised section 73.

[0105] The sunken section 71 in this embodiment is of a similar U-shapeto that in Embodiment 2 and is formed so that its center coincides withthe center line CL, and there is a difference in level between thesunken section 71, and raised section 72 and raised section 73 on eitherside of the sunken section 71, in the same way as in Embodiment 1, sothat a solder ball 400 is dropped into the sunken section 71—that is,between raised section 72 and raised section 73—under the force ofgravity, and is temporarily fixed so that the center of the solder ball400 substantially coincides with the center line CL on the sunkensection 71 and does not move in the virtual right angle axis directionbetween the two pads. As a result, the solder ball 400 will no longermove even if subjected to some kind of stress in the virtual right angleaxis direction (direction A or direction B shown in FIG. 11) due to thesubsequent injection of nitrogen gas, etc., or vibration when theoptical apparatus 200 moves, for example. The dimensions of the U-shapecan be set in the same way as in Embodiment 2.

[0106] In this embodiment, a U-shaped sunken section 71 is formed on alead wiring pad 70 centered on the center line CL with the opening sidefacing downward, as in Embodiment 2, but a sunken section of a differentshape centered on the center line CL may also be formed as long as itsshape enables a solder ball 400 to be dropped into it under the force ofgravity.

[0107] The difference in level formed by the sunken section 71 need notbe a sharply-defined difference in level as shown in FIG. 11, but, forexample, may be configured so that the sunken section 71 sinks gentlybelow raised section 72 and raised section 73 on a curved surface, ormay be configured so that the sunken section 71 sinks gently belowraised section 72 and raised section 73 on an inclined surface.

[0108] Thus, with an integrated lead suspension of this embodiment,through the provision of a sunken section 71 in a lead wiring pad 70, inthe same way as in the other embodiments described above, the center ofa solder ball 400 substantially coincides with the center line CL of thelead wiring pad 70, and is temporarily fixed so that it does not move inthe virtual right angle axis direction between the two pads, as a resultof which the solder ball 400 will no longer move in the right angle axisdirection even if subjected to some kind of stress in the virtual rightangle axis direction due to subsequent injection of an inert gas ormovement of the optical apparatus 200, for example, thereby enabling thegood solder connection state shown in FIG. 5 to be achieved.

[0109]FIG. 12 comprises oblique drawings showing enlarged views of themain parts in an integrated lead suspension according to Embodiment 7 ofthe present invention. FIG. 12(A) is a drawing showing pads of the samekind as conventional lead wiring pads during the process of manufacture,and FIG. 12(B) is a drawing showing lead wiring pads of this embodiment.The only difference between this embodiment and Embodiment 1 is that theshape of the lead wiring pads 80 a shown in FIG. 12(B) is different.However, in order to form lead wiring pads 80 a, use of an additive typemanufacturing method is necessary, and therefore the manufacturingmethod for an integrated lead suspension of this embodiment is limitedto an additive type. Otherwise the configuration is the same as that ofthe integrated lead suspension according to Embodiment 1 shown in FIGS.1 through 6.

[0110] With a lead wiring pad 80 a of this embodiment, a lead wiring pad80 of the same kind as a conventional lead wiring pad shown in FIG.12(A) is first formed, in the same way as in Embodiment 1, and thencopper plating is added to the areas on both sides excluding thevicinity of the center line CL on the surface of this pad 80. The methodof forming a lead wiring pad 80 of the same kind as a conventional leadwiring pad is the same as in Embodiment 1.

[0111] A recessed groove section (recessed section) 81, and a raisedsection 82 and raised section 83, are formed by coating areas other thanthe vicinity of the center line CL (necessary areas) on the lead wiringpad 80 with a resist, performing Cu (copper) plating, and then removingthe resist.

[0112] Due to the fact that a recessed groove section 81 of thisembodiment is formed so that its center coincides with the center lineCL as in Embodiment 1, and that there is a difference in level betweenthe recessed groove section 81, and raised section 82 and raised section83 on either side of the recessed groove section 81, as in Embodiment 1,a solder ball 400 is dropped into the recessed groove section 81—thatis, between raised section 82 and raised section 83—under the force ofgravity, and is temporarily fixed so that the center of the solder ball400 substantially coincides with the center line CL on the recessedgroove section 81 and does not move in the virtual right angle axisdirection between the two pads. As a result, the solder ball 400 will nolonger move even if subjected to some kind of stress in the virtualright angle axis direction (direction A or direction B shown in FIG.12(B)) due to the subsequent injection of nitrogen gas, etc., orvibration when the optical apparatus 200 moves, for example. Thedimensions of the recessed groove section can be set in the same way asin Embodiment 1.

[0113] In this embodiment, a recessed groove section 81 of the same kindof shape as in Embodiment 1 is formed in a lead wiring pad 80 a,centered on the center line CL, but a recessed section of a differentshape may also be formed centered on the center line CL, as long as itsshape enables a solder ball 400 to be dropped into it under the force ofgravity.

[0114] The difference in level formed by the recessed groove section 81need not be a sharply-defined difference in level as shown in FIG. 12,but, for example, may be configured so that the recessed groove section81 sinks gently below raised section 82 and raised section 83 on acurved surface, or may be configured so that the recessed groove section81 sinks gently below raised section 82 and raised section 83 on aninclined surface.

[0115] Thus, with an integrated lead suspension of this embodiment,through the provision of a recessed groove section 81 in a lead wiringpad 80 a, in the same way as in the other embodiments described above,the center of a solder ball 400 substantially coincides with the centerline CL of the lead wiring pad 80 a, and is temporarily fixed so that itdoes not move in the virtual right angle axis direction between the twopads, as a result of which the solder ball 400 will no longer move inthe right angle axis direction even if subjected to some kind of stressin the virtual right angle axis direction due to subsequent injection ofan inert gas or movement of the optical apparatus 200, for example,thereby enabling the good solder connection state shown in FIG. 5 to beachieved.

[0116]FIG. 13 comprises oblique drawings showing enlarged views of themain parts in an integrated lead suspension according to Embodiment 8 ofthe present invention. FIG. 13(A) is a drawing showing pad base sectionsformed by etching, etc., on a polyimide layer, which is insulatingpolymeric material, during the process of manufacture, and FIG. 13(B) isa drawing showing lead wiring pads of this embodiment.

[0117] The only differences between this embodiment and Embodiment 1 arethat the pad base sections 95 shown in FIG. 13(A) are formed on apolyimide layer 17, and that the shape of the lead wiring pads 90 shownin FIG. 13(B) is different. However, in order to form lead wiring pads90 on the pad base sections 95, use of an additive type manufacturingmethod is necessary, and therefore the manufacturing method for anintegrated lead suspension of this embodiment is limited to an additivetype. Otherwise the configuration is the same as that of the integratedlead suspension according to Embodiment 1 shown in FIGS. 1 through 6.

[0118] Pad base sections 95 of this embodiment are formed, for example,by a process in which the polyimide layer 17 is etched when anintegrated lead suspension is manufactured. At this time, followingnormal etching to obtain the external shape of pad base sections 95 fromthe polyimide layer 17, half-etching is performed with resist applied ina shape excluding U-shaped underlying recessed section 96 parts with theopening side facing downward so that the center line CL and center axiscoincide. If the polyimide layer 17 is a photosensitive polyimide layer,pad base sections 95 are formed by a process in which the polyimidelayer 17 is exposed and developed when an integrated lead suspension ismanufactured, and the U-shaped underlying recessed sections 96, baseraised sections 97, and base raised sections 98 shown in FIG. 13(A) areformed by performing exposure and development after applying resist in ashape excluding the U-shaped underlying recessed section 96 parts.

[0119] Next, as with a conventional additive type manufacturing method,leads 10, lead wiring pads 90, and so forth, are formed on the polyimidelayer 17 by copper plating. At this time, raised sections 92 and raisedsections 93 forming the two sides of each lead wiring pad 90 formed bycopper plating are formed to the same height as in Embodiment 1 on thebase raised sections 97 and base raised sections 98 of the polyimidelayer 17. However, a greater degree of depression occurs on eachU-shaped underlying recessed section 96 of the polyimide layer 17 thanon the areas on either side, as in Embodiment 6, and a U-shaped sunkensection (recessed section) 91 is formed in each lead wiring pad 90formed by copper plating. The dimensions of the U-shape can be set inthe same way as in Embodiment 2.

[0120] Due to the fact that a U-shaped sunken section 91 of thisembodiment is formed so as to be of a similar U-shape to that inEmbodiment 6 and so that its center coincides with the center line CL,and that there is a difference in level between the sunken section 91,and raised section 92 and raised section 93 on either side of the sunkensection 91, as in Embodiment 1, a solder ball 400 is dropped into thesunken section 91—that is, between raised section 92 and raised section93—under the force of gravity, and is temporarily fixed so that thecenter of the solder ball 400 substantially coincides with the centerline CL on the sunken section 91 and does not move in the virtual rightangle axis direction between the two pads. As a result, the solder ball400 will no longer move even if subjected to some kind of stress in thevirtual right angle axis direction (direction A or direction B shown inFIG. 13(B)) due to the subsequent injection of nitrogen gas, etc., orvibration when the optical apparatus 200 moves, for example.

[0121] In this embodiment, a sunken section 91 of the same kind ofU-shape as in Embodiment 6 is formed in a lead wiring pad 90, centeredon the center line CL, but a sunken section of a different shape mayalso be formed centered on the center line CL, as long as its shapeenables a solder ball 400 to be dropped into it under the force ofgravity.

[0122] The difference in level formed by the sunken section 91 need notbe a sharply-defined difference in level as shown in FIG. 13, but, forexample, may be configured so that the sunken section 91 sinks gentlybelow raised section 92 and raised section 93 on a curved surface, ormay be configured so that the sunken section 91 sinks gently belowraised section 92 and raised section 93 on an inclined surface.

[0123] Thus, with an integrated lead suspension of this embodiment,through the provision of a sunken section 91 in a lead wiring pad 90, inthe same way as in the other embodiments described above, the center ofa solder ball 400 substantially coincides with the center line CL of thelead wiring pad 90, and is temporarily fixed so that it does not move inthe virtual right angle axis direction between the two pads, as a resultof which the solder ball 400 will no longer move in the right angle axisdirection even if subjected to some kind of stress in the virtual rightangle axis direction due to subsequent injection of an inert gas ormovement of the optical apparatus 200, for example, thereby enabling thegood solder connection state shown in FIG. 5 to be achieved.

[0124]FIG. 14 comprises oblique drawings showing enlarged views of themain parts in an integrated lead suspension according to Embodiment 9 ofthe present invention. FIG. 14(A) is a drawing showing pad base sectionsformed by etching, etc., on a polyimide layer, which is insulatingpolymeric material, during the process of manufacture, and FIG. 14(B) isa drawing showing lead wiring pads of this embodiment.

[0125] The only difference between this embodiment and Embodiment 8 isthat the shape of the pad base sections 105 shown in FIG. 14(A) and theshape of the lead wiring pads 100 shown in FIG. 14(B) are different, thefact that the manufacturing method for an integrated lead suspension ofthis embodiment is limited to an additive type being a point ofsimilarity with Embodiment 8. Otherwise the configuration is the same asthat of the integrated lead suspension according to Embodiment 8 shownin FIG. 13.

[0126] Pad base sections 105 of this embodiment are formed, for example,by a process in which the polyimide layer 17 is etched when anintegrated lead suspension is manufactured. At this time, followingnormal etching to obtain the external shape of pad base sections 105from the polyimide layer 17, half-etching is performed with resistapplied in a shape excluding V-shaped underlying recessed section 106parts with the opening side facing downward so that the center line CLand center axis coincide. If the polyimide layer 17 is a photosensitivepolyimide layer, pad base sections 105 are formed by a process in whichthe polyimide layer 17 is exposed and developed when an integrated leadsuspension is manufactured, and the V-shaped underlying recessedsections 106, base raised sections 107, and base raised sections 108shown in FIG. 14(A) are formed by performing exposure and developmentafter applying resist in a shape excluding the V-shaped underlyingrecessed section 106 parts.

[0127] Next, as with a conventional additive type manufacturing method,leads 10, lead wiring pads 100, and so forth, are formed on thepolyimide layer 17 by copper plating. At this time, raised sections 102and raised sections 103 forming the two sides of each lead wiring pad100 formed by copper plating are formed to the same height as inEmbodiment 1 on the base raised sections 107 and base raised sections108 of the polyimide layer 17. However, a greater degree of depressionoccurs on each V-shaped underlying recessed section 106 of the polyimidelayer 17 than on the areas on either side, and a V-shaped sunken section(recessed section) 101 is formed in each lead wiring pad 100 formed bycopper plating. The dimensions of the V-shape can be set in the same wayas in Embodiment 3.

[0128] Due to the fact that a V-shaped sunken section 101 of thisembodiment is formed so that the center of the V coincides with thecenter line CL, and that there is a difference in level between thesunken section 101, and raised section 102 and raised section 103 oneither side of the sunken section 101, as in Embodiment 1, a solder ball400 is dropped into the sunken section 101—that is, between raisedsection 102 and raised section 103—under the force of gravity, and istemporarily fixed so that the center of the solder ball 400substantially coincides with the center line CL on the sunken section101 and does not move in the virtual right angle axis direction betweenthe two pads. As a result, the solder ball 400 will no longer move evenif subjected to some kind of stress in the virtual right angle axisdirection (direction A or direction B shown in FIG. 14(B)) due to thesubsequent injection of nitrogen gas, etc., or vibration when theoptical apparatus 200 moves, for example.

[0129] In this embodiment, a V-shaped sunken section 101 is formed in alead wiring pad 100, centered on the center line CL, but a sunkensection of a different shape may also be formed centered on the centerline CL, as long as its shape enables a solder ball 400 to be droppedinto it under the force of gravity.

[0130] The difference in level formed by the sunken section 101 need notbe a sharply-defined difference in level as shown in FIG. 14, but, forexample, may be configured so that the sunken section 101 sinks gentlybelow raised section 102 and raised section 103 on a curved surface, ormay be configured so that the sunken section 101 sinks gently belowraised section 102 and raised section 103 on an inclined surface.

[0131] Thus, with an integrated lead suspension of this embodiment,through the provision of a sunken section 101 in a lead wiring pad 100,in the same way as in the other embodiments described above, the centerof a solder ball 400 substantially coincides with the center line CL ofthe lead wiring pad 100, and is temporarily fixed so that it does notmove in the virtual right angle axis direction between the two pads, asa result of which the solder ball 400 will no longer move in the rightangle axis direction even if subjected to some kind of stress in thevirtual right angle axis direction due to subsequent injection of aninert gas or movement of the optical apparatus 200, for example, andmoreover, the fact that the shape of the sunken section 101 is a V alsomakes it difficult for the solder ball 400 to move toward the apex ofthe V, and so makes the solder ball 400 all the more stable, therebyenabling the good solder connection state shown in FIG. 5 to beachieved.

[0132] In the above-described embodiments, when a bonding pad and leadwiring pad are connected by means of a solder ball, the virtual angleformed between that bonding pad and lead wiring pad is assumed to be aright angle, but this angle may be changed to any angle as long as it isan angle that enables a solder ball 400 to be caught.

[0133] Similarly, in the above-described embodiments, a lead wiring padand bonding pad fixes a flexure as to both be at an angle of 45 degreesabove the horizontal, but this angle also may be changed to any angle aslong as it is an angle that enables a solder ball 400 to be caught.

[0134] Also, in the above-described embodiments, cases of a groove, aV-shape, and a U-shape are mentioned with regard to the shape ofrecessed sections, but the advantages of the present invention can alsobe obtained with recessed sections of any shape, including circular,oval, rectangular, or rhomboidal.

[0135] As described above, with a integrated lead suspension of thepresent invention, through the provision of a recessed section in a leadwiring pad, the center of a solder ball substantially coincides with thecenter line of the lead wiring pad, and is temporarily fixed so that itdoes not move in a virtual right angle axis direction between the twopads, as a result of which the solder ball no longer moves in a rightangle axis direction even if subjected to some kind of stress in thevirtual right angle axis direction due to subsequent injection of aninert gas, movement of the optical apparatus, or the like, therebyenabling a good solder connection state to be achieved.

[0136] Also, with the present invention in which a recessed section in alead wiring pad is made V-shaped, in addition to the above-describedadvantage, the fact that the shape of the recessed section is a V alsomakes it difficult for a solder ball to move toward the apex of the V,and so makes the solder ball more stable, thereby enabling a good solderconnection state to be achieved.

What is claimed:
 1. An integrated lead suspension, comprising: a leadwiring pad provided on a flexure section of the suspension, a bondingpad provided on a slider of a head gimbal section of the suspension, anda solder ball that is placed between the lead wiring pad and the bondingpad, so that the solder ball is melted to solder the lead wiring pad andthe bonding pad together; and wherein the suspension comprises arecessed section into which the solder ball is dropped from the surfaceof the lead wiring pad, using gravitational force, adjacent to thecenter line of the surface of the lead wiring pad.
 2. The integratedlead suspension of claim 1, wherein in the recessed section, adifference in level is provided between a portion into which the solderball is dropped and portions on both sides of said portion.
 3. Theintegrated lead suspension of claim 1, wherein in the recessed section,a curved surface is formed between a portion into which the solder ballis dropped and portions on both sides of said portion.
 4. The integratedlead suspension of claim 1, wherein in the recessed section, an inclinedsurface is formed between a portion into which the solder ball isdropped and portions on both sides of said portion.
 5. The integratedlead suspension of claim 1, wherein in the recessed section, distancesfrom the center line of a portion into which the solder ball is droppedto both sides of the recessed section are equal.
 6. The integrated leadsuspension of claim 1, wherein in the recessed section, a portion intowhich the solder ball is dropped has a groove shape that is parallel tothe center line.
 7. The integrated lead suspension of claim 1, whereinin the recessed section, a portion into which the solder ball is droppedis a notched section.
 8. The integrated lead suspension of claim 1,wherein the recessed section has a U-shape such that an open side of therecessed section faces downward and portions on both sides of therecessed section are parallel to the center line.
 9. The integrated leadsuspension of claim 1, wherein the recessed section has a V-shape suchthat an open side of the recessed section faces downward and portions onboth sides of the recessed section extend toward the open side from anapex located on the center line.
 10. A method of constructing anintegrated lead suspension, comprising: providing a lead wiring pad on aflexure section of the suspension and a bonding pad on a slider of ahead gimbal section of the suspension; placing a solder ball between thelead wiring pad and the bonding pad, such that the solder ball is meltedto solder the lead wiring pad and the bonding pad together; wherein whena lead wiring pad is formed using etching technology, a recessed sectionis simultaneously formed in the suspension into which the solder ball isdropped from the surface of the lead wiring pad, using gravitationalforce, in the vicinity of the center line of the surface of the leadwiring pad.
 11. A method of constructing an integrated lead suspension,comprising: providing a lead wiring pad on a flexure section of thesuspension and a bonding pad on a slider of a head gimbal section of thesuspension; placing a solder ball between the lead wiring pad and thebonding pad, such that the solder ball is melted to solder the leadwiring pad and the bonding pad together; wherein the method ofconstructing further comprises the steps of: first forming the leadwiring pad having a flat surface; and thereafter providing a recessedsection into which the solder ball is dropped from the flat surface ofthe lead wiring pad, using gravitational force, in the vicinity of acenter line of the surface of the lead wiring pad.
 12. The method ofclaim 11, wherein the recessed section is formed by etching thesuspension.
 13. The method of claim 11, wherein the recessed section isformed by bending the suspension.
 14. The method of claim 11, whereinthe recessed section is formed by die pressing the suspension.
 15. Themethod of claim 11, wherein when the integrated lead suspension is anadditive type, and the method comprises the steps of: first forming alead wiring pad having a flat surface using copper plating technology;and thereafter causing protrusion by plating additional copper onportions on both sides thereof excluding the vicinity of the center lineof the surface of the lead wiring pad to provide the recessed section.16. The method of claim 11, wherein the integrated lead suspension is anadditive type, and the construction method comprises the steps of: firstforming an underlying recessed section using etching technology on anunderlying layer of the lead wiring pad; and thereafter forming therecessed section by forming a lead wiring pad using copper platingtechnology on the underlying layer.